$A$ field line is shown in the figure. This field line cannot represent:

$A$ hollow cylinder has a charge $q$ coulomb within it. If $\phi$ is the electric flux in unit of $V-m$ associated with the curved surface $C$, the flux linked with the plane surface $A$ in unit of $V-m$ will be. $[\epsilon_0 = \text{permittivity of free space}]$

Careful measurement of the electric field at the surface of a black box indicates that the net outward flux through the surface of the box is $8.0 \times 10^{3} \; N m^{2} / C$.
$(a)$ What is the net charge inside the box?
$(b)$ If the net outward flux through the surface of the box were zero,could you conclude that there were no charges inside the box? Why or why not?

The electric flux through surface $S_1$ is:

The figure shows electric field lines due to a charge configuration. From this,we conclude that:

The $S.I.$ unit of electric flux is